Abstract

PENA, R  and  DUMAS, S. Development of the retina in spotted sand bass Paralabrax maculatofasciatus (Percoidei: Serranidae) larvae under culture conditions. Cienc. mar [online]. 2007, vol.33, n.3, pp.293-300. ISSN 0185-3880.

We describe the development of the retina in spotted sand bass Paralabrax maculatofasciatus larvae under culture conditions, using histological techniques. Retinal development in the spotted sand bass larvae followed a pattern previously described for other teleost species. Two periods of active differentiation were observed. The first occurred during the yolk-sac stage (from hatching to day 2 after hatching) as preparation for the onset of exogenous feeding. During this period, the eye showed negative allometric growth (growth coefficient = 0.5). At the time of first feeding (day 2), total length (TL) was 2.58 ± 0.26 mm (mean ± SD), the eye became pigmented and single cones were the only photoreceptors observed in the retina. After first feeding, a slightly positive allometric growth of the eye was observed (growth coefficient = 1.11). The second period occurred during the transformation to juvenile stage. Presumptive double cones were first observed on day 14 (TL = 5.37 ± 0.58 mm) and presumptive rods on day 22 after hatching (TL = 7.23 ± 0.99 mm). From day 22 onwards, the visual system was formed by a duplex retina with both rod and cone photoreceptors present.

Keywords : eye development; retinal structure; Paralabrax maculatofasciatus; photoreceptors.

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